The first step is to cut your 2x4s to the appropriate length. We went with 5 foot long pieces and the sides at 4 feet. It is all dependent on where you are going to store the wood and how much wood you have.
The next step is in determining how far you want the wood off the ground. The image that came with the metal rack, had the horizontal 2x4's on the ground. This will lift the firewood about 3 inches off the ground. If you flip the brackets over like we have pictures above, then the firewood would be about 6 inches off the ground.
Next step is place the wood into each of the brackets. You may need a hammer to pound the wood into the brackets in the case they it is snug. Once they are in place, screw in the screws that come with the metal racks into the wood. This make the stand that much more sturdy.
Once you have it built, its a matter of clearing out a space for your rack.
Start stacking your wood. If you use both large and smaller pieces regularly, I would recommend stacking one side with larger pieces and the other side with smaller, rather than putting all the large pieces on the bottom. Then you won't be digging through the stack every time you want a large log.
Viola, you have yourself a firewood stand!